Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 12/22/2003
Publication Date: 4/29/2004
Citation: Bryla, D.R., Strik, B.C. Variation in plant and soil water relations among irrigated blueberry cultivars planted at two distinct in-row spacings. 8th International Symposium on Vaccinium Culture, Oeiras, Portugal and Seville, Spain, May 3-8. 2004. p. P28. Interpretive Summary:
Technical Abstract: A study was conducted to determine the effect of in-row spacing on plant and soil water relations in 'Duke', 'Bluecrop', and 'Elliott' highbush blueberry and to identify possible mechanisms that may enhance the ability of these cultivars to tolerate short-term episodes of soil water deficit. Changes in soil water content, stem water potential, and leaf stomatal conductance were measured at 4 years after planting on well-irrigated plants of each cultivar spaced 0.5 or 1.2 m within rows on raised beds (0.3 m high) and 3.0 m between rows. Irrigation (711 mm) was applied equally to all treatments by overhead sprinklers during the dry summer months from mid-May to early-September. Close spacing significantly reduced individual shoot dry weight, but also significantly increased crop light interception and water uptake from 0-0.6 m soil depth compared to plants spaced further apart. Spacing had little effect, however, on plant water relations of the cultivars. Independent of cultivar and spacing, stomatal conductance decreased rapidly as stem water potential approached -0.6 to -0.8 MPa. Among cultivars, 'Bluecrop' had the lowest root mass and root:shoot dry weight ratio at either spacing, while 'Elliott' had the highest. 'Duke', however, produced the deepest root system, extracting a significant amount of water below 0.6 m when plants were closely spaced. 'Duke' also maintained, on average, higher stem water potentials and greater stomatal conductance as soil water was depleted than the other cultivars.